ABSTRACT
The mirror carp (Cyprinus carpio) belongs to the cyprinids, the world's largest and most important fish family in aquaculture. The fat content and the fillet yield are important parameters in the marketing of carp. Although the influence of the environment on the body composition of the carp has been well studied, there is little research in the field of breeding. For this purpose, precise phenotyping is indispensable. Therefore, during this study a total of 33 mirror carps were examined using computed tomography (CT) technology. First, the fish were examined alive. Total body weight and linear measurements such as lengths, height and circumferences were measured, and ultrasound was used to determine the back-fat thickness. The fish were then slaughtered and whole body scans of all fish using CT were made. The carps were filleted and the fillets with skin were chemically analyzed. In order to predict the chemical fillet fat content, thickness measurements and volume calculations of the back fat were carried out using CT. Compared to the CT-based back-fat thickness measurement correlated with the results from the chemical analysis ( R 2 = 0.62 ), the CT-based volume measurement of the back fat leads to a higher coefficient of determination ( R 2 = 0.85 ). Prediction results can still be improved by adding linear measurements. The in vivo ultrasound (US) examination of the back-fat thickness was compared with the CT back-fat thickness results. The measurements of the back-fat thickness took place at similar positions in the fish. Coefficients of determination ( R 2 ) of 0.63 to 0.77 were obtained. The back fat in mirror carp proved to be an interesting area for determining the fillet fat content. The evaluation of the fillet yield resulted in a mean value of 42.89â¯% with a standard deviation of ± 2.43 . Fillet yield (%) correlated with CT-based fillet thickness measurement resulted in a moderate coefficient of determination ( R 2 of 0.45). A similar coefficient of determination was achieved with selected linear measurements.
ABSTRACT
OBJECTIVES: Vaccination is one of the most effective methods to keep up the health status in humans and in livestock. Therefore, farm animals are vaccinated several times during their lifetime. Although vaccines are being checked regarding their local reactogenicity, side effects occur frequently-especially in the case of the application of adjuvanted products. Many reports exist about local reactions in sheep. The present study aimed at testing MRI as a method to document injection site reactions three-dimensionally. DESIGN: Two groups of Merino lambs (n=16 each) were vaccinated subcutaneously into the left neck side. Two different, licensed inactivated vaccines were used. Both groups of lambs were anaesthetised and scanned using MRI at days 1, 3, 8, 15, 22 and 29 after vaccination. SETTING: The study was performed on a commercial-like farm. PARTICIPANTS: Thirty-two Merino lambs entered the experiment, 16 male and 16 female ones (one animal died at day 22 after vaccination). At first examination day they were approximately three months old. PRIMARY AND SECONDARY OUTCOME MEASURES: Volume differences were measured between vaccination and control neck side to evaluate the time pattern of local tissue reactions. RESULTS: Local tissue reactions were visible on the skin surface and also appeared in deeper tissue layers on MRI. These deeper reactions would not have been found without MRI or, alternatively, without sacrificing the animals. Some of these extensive local reactions lasted for more than 29 days. CONCLUSIONS: The in vivo MRI results proved suitable to record local tissue reactions in terms of three-dimensional extent over a longer period of time in large farm animals without the need to sacrifice test animals. A three-dimensional MRI examination of the injection site during regulatory licensing studies offers an objective evaluation that could be used in a benefit-risk assessment of veterinary vaccines. TRIAL REGISTRATION NUMBER: District Government of Upper Bavaria:55.2-1-54-2532-2-13.
